Buggy code:
public class FastAnalyzer { private static final Pattern ENDS_WITH_SINGLE_LINE_COMMENT_PATTERN = Pattern . compile ( "////.*$" ) ; private static final Pattern CONTAINS_SINGLE_LINE_COMMENT_PATTERN = Pattern . compile ( "////.*$" , Pattern . MULTILINE ) ; private static final Pattern BEGIN_MULTI_LINE_COMMENT_PATTERN = Pattern . compile ( "//\\*" , Pattern . MULTILINE ) ; private static final Pattern COMPLETE_MULTI_LINE_COMMENT_PATTERN = Pattern . compile ( "//\\*.*\\*//" , ( ( Pattern . MULTILINE ) | ( Pattern . DOTALL ) ) ) ; private static final Pattern PARAM_PATTERN = Pattern . compile ( "([\\[\\]:\\w]+)\\s+([\\w]+)" ) ; private static final Pattern IMPORT_PATTERN = Pattern . compile ( "import\\s+([\\w\\:]+)\\s*;" ) ; private static final Pattern INCOMPLETE_IMPORT_PATTERN = Pattern . compile ( "import\\s+[\\w\\:]*\\z" ) ; private static final Pattern EXTENSION_PATTERN = Pattern . compile ( "extension\\s+([\\w\\:]+)\\s*(reexport)?\\s*;" ) ; private static final Pattern INCOMPLETE_EXTENSION_PATTERN = Pattern . compile ( "extension\\s+[\\w\\:]*\\z" ) ; private static final Pattern FUNCTION_PATTERN = Pattern . compile ( "((\\w+)\\s+)?(create\\s+([\\w:]+)(\\s+(\\w+))?\\s+)?([\\w:]+)\\s*\\(\\s*([\\[\\]:\\w\\s\\,]+)?\\s*\\)\\s*:\\s*[^;]*\\z" ) ; private static final Pattern AROUND_PATTERN = Pattern . compile ( "around\\s+([\\w:*]+)\\s*\\(\\s*([\\[\\]:\\w\\s\\,]+)?[\\s,*]*\\)\\s*:\\s*[^;]*\\z" ) ; private static final Pattern TYPEDECL_PATTERN = Pattern . compile ( "(;|\\A)\\s*\\w+(\\s*\\[\\w+\\]*)?\\s*\\w+\\s*\\(([\\[\\]:\\w\\s,]*)\\z" ) ; private static final Pattern TYPEDECL_PARAM_PATTERN = Pattern . compile ( "(,|\\(|\\A)\\s*[\\[\\]:\\w]*\\z" ) ; private FastAnalyzer ( ) { } public static boolean isInsideTypeDeclaration ( final String s ) { } public static boolean isInsideExtensionImport ( final String s ) { } public static boolean isInsideImport ( final String s ) { } public static boolean isInsideExpression ( final String s ) { } public static boolean isInsideComment ( final String input ) { } public static final List < String > findImports ( final String template ) { } public static final List < String > findExtensions ( final String template ) { } public static final Stack < Set < LazyVar > > computeStack ( String toAnalyze ) { } private static void fillParams ( final Set < LazyVar > vars , final String params ) { } public static final Partition computePartition ( final String str ) { } public static final ExecutionContext computeExecutionContext ( final String str , ExecutionContext ctx , final List < Extension > extensions ) { final Partition p = FastAnalyzer . computePartition ( str ) ; <START_BUG> if ( ( p == ( Partition . EXPRESSION ) ) || ( p == ( Partition . TYPE_DECLARATION ) ) ) { <END_BUG> final List < String > imports = FastAnalyzer . findImports ( str ) ; final List < String > extensionImports = FastAnalyzer . findExtensions ( str ) ; final XtendFile tpl = new XtendFile ( ) { private String fqn ; public String getFullyQualifiedName ( ) { return fqn ; } public void setFullyQualifiedName ( String fqn ) { this . fqn = fqn ; } public String [ ] getImportedNamespaces ( ) { return imports . toArray ( new String [ imports . size ( ) ] ) ; } public String [ ] getImportedExtensions ( ) { return extensionImports . toArray ( new String [ extensionImports . size ( ) ] ) ; } public List < Extension > getExtensions ( ) { return extensions ; } public void analyze ( ExecutionContext ctx , Set < AnalysationIssue > issues ) { } public List < Extension > getPublicExtensions ( ResourceManager rm , ExecutionContext ctx ) { return extensions ; } public List < Extension > getPublicExtensions ( ResourceManager resourceManager , ExecutionContext ctx , Set < String > flowoverCache ) { return extensions ; } public List < Around > getArounds ( ) { return Collections . emptyList ( ) ; } } ; ctx = ctx . cloneWithResource ( tpl ) ; final Stack < Set < LazyVar > > s = FastAnalyzer . computeStack ( str ) ; for ( final Iterator < Set < LazyVar > > iter = s . iterator ( ) ; iter . hasNext ( ) ; ) { final Set < LazyVar > vars = iter . next ( ) ; for ( final Iterator < LazyVar > iterator = vars . iterator ( ) ; iterator . hasNext ( ) ; ) { final LazyVar v = iterator . next ( ) ; Type vType = null ; if ( ( v . typeName ) != null ) { vType = ctx . getTypeForName ( v . typeName ) ; } else { vType = new org . eclipse . xtend . expression . ExpressionFacade ( ctx ) . analyze ( v . expression , new HashSet < AnalysationIssue > ( ) ) ; if ( v . forEach ) { if ( vType instanceof ParameterizedType ) { vType = ( ( ParameterizedType ) ( vType ) ) . getInnerType ( ) ; } else { vType = null ; } } } ctx = ctx . cloneWithVariable ( new org . eclipse . xtend . expression . Variable ( v . name , vType ) ) ; } } } return ctx ; } }

Fix:
if ( ( ( p == ( Partition . EXPRESSION ) ) || ( p == ( Partition . TYPE_DECLARATION ) ) ) || ( p == ( Partition . DEFAULT ) ) ) {